Searching for pattern with characters and numerics in SAS

I am examining data quality and am trying to see how many rows are populated properly. The field should contain a string with one character followed by nine numerical.

Ex.

A123456789 B123531490 C319861045

I have tried using PRXMATCH function, but I am unsure if i use the proper syntax. I have also tried using PROC SQL with "Where not like "[A-Z][0-9][0-9]" and so on. My feeling is that this should not be difficult to perform, does anyone have a solution?

Best regards